The present invention relates in general to smart cards, and, more particularly, to smart cards in which the internal semiconductor devices may be removed or replaced by an authorized party.
Smart cards have been developed for a wide variety of uses. Smart cards typically include an integrated circuit with a memory element (ROM or RAM) and a control unit, such as a microprocessor or microcomputer. The structure of the integrated circuit is such that it is embedded in a portion of a plastic card having dimensions and physical characteristics of standard credit cards in widespread use. The embedded integrated circuit may include a plurality of terminals on an exterior surface of the card to permit the internal and external transfer of signals to and from the card. Such a smart card is commonly known as a contact smart card. The transfer of signals is accomplished by inserting the card into a compatible reader which provides electrical contacts to interconnect the integrated circuit in the card to a card information processing unit associated with the reader. The reader typically provides power for operating the card, and data is transferred to and from the card whenever it is inserted into the reader. Conversely, a contactless smart card includes an internal power supply and an antenna such that data may be transferred without having to make direct electrical contact the reader.
Since the memories in a smart card can be encoded to identify the card uniquely for a particular application, such a card may be utilized in a number of different application areas. When the sophisticated security features of such cards are employed, the cards may be used as access keys for computer systems, data bases, data networks, or for physical access control to hotel rooms, factories, offices, and the like. Smart cards are increasingly used to access automated bank terminals and permit transaction information to be updated each time a transaction is made so that the card uniquely tracks the authority of the user by information which is written into the memory of the integrated circuit embedded in the card.
Smart cards may also be utilized as small portable files, or records for different types of information, such as personal telephone directories, detailed medical profiles, insurance information, and the like. Smart cards are also useful for point-of-sale credit or debit operations, either in on-line or off-line systems, such as point-of-sale terminals in grocery stores, public telephones and the like.
Smart cards are typically more expensive than regular credit cards because of the integrated circuits embedded in the cards. The plastic material making up the body of a smart card tends to crack and wear out. Additionally, the information printed on the cards may become obsolete. In either situation, it becomes necessary to replace the card. As the integrated circuit is typically embedded in the card, the expensive integrated circuit has been discarded along with the worn-out or obsolete body. It is thus desirable to provide a smart card in which the expensive integrated circuit may be removed from the card body when the body is worn-out or obsolete.
For example, one such smart card having a removable integrated circuit is taught in U.S. Pat. No. 4,511,796. The smart card includes an integrated circuit which may be inserted or removed by simply rotating the integrated circuit into and out of the card. While the integrated circuit may be easily replaced or transferred to another card, there is no provision to prevent unauthorized access to the integrated circuit. Such unauthorized access may lead to tampering, theft, fraud or misuse.
Accordingly, there is a need for a smart card having an integrated circuit which may be removed or replaced by authorized personnel only. There is also a need for a smart card which provides an indication of tampering with the integrated circuit. Preferably, removal of the integrated circuit would be easy to implement while manufacture of such as smart card would be relatively inexpensive.